Ki-27 too durable & strange behavior

[RPS69]

Originally Posted by Ice_Eagle

A quick look at Ki-27's model shows a wing spar.

He was talking about a wing spar hit box, not the wing spar representation itself.

[taly001]

The Ki-27 bounces its tail skid on the ground under takeoff power when stationary - propellor wash on elevator? Maybe the fuselage damage model was made tough too prevent this snapping apart on ground. But the Ki-27 certainly can't take much damage in il2 air battles!

What confuses me more is that the Ki-27 is a super-stable gun platform? Almost laser gun like!

[Pursuivant]

Originally Posted by Ice_Eagle

A quick look at Ki-27's model shows a wing spar.

Good. I lack the tools to view DM, hook placement, etc. so I have to guess about a number of things.

My experience is that actual physical models, including the model which includes "critical hit" areas, are OK for the planes included in Pacific Fighters, but that they sometimes suffer from errors in hook placement, and inconsistent or incorrect assumptions about engine and airframe durability. The planes which have the worst DM are the planes from the earliest games in the series, and the earliest fan-produced models. The Me-232 and Me-231, Ar-196, and PZL P.11 are probably the worst offenders, but there are problems with other planes.

My testing revealed a lot of cases where "hooks" (i.e., placement for origin point for things like smoke, fire, fuel leak effects) were improperly placed, were reversed, or were missing. In a few cases, it looks like coding errors "moved" vital systems within the plane so hits to what should be "empty" areas of the airplane result in damage.

Much more commonly, there are inconsistent or incorrect assumptions about how much damage a particular system can take. For example, the F4U, F6F and P-47 all used the same engine, but there are variations in how much damage it take to destroy each plane's engine. (I forget which plane is the most vulnerable in the group, I think it's the F6F.) As another example, the "fatal damage" textures for the TBF's wing show the wing missing less wing surface area than the plane was historically able to survive!

http://s3.crackedcdn.com/phpimages/a...129573.jpg?v=1

[Pursuivant]

Originally Posted by taly001

The Ki-27 bounces its tail skid on the ground under takeoff power when stationary - propeller wash on elevator?

That seems unlikely. I don't think that IL2 models prop-wash effects on control surfaces (or following planes)

I'm guessing that the FM has the engine generating enough thrust and torque at full power that it starts to lift the plane's tail.

The idea that the Ki-27 "didn't want to sit still" if the engine was run up to full power while it was stationary might just make sense since you've got a somewhat lightly built plane with a reasonably powerful engine.

I bet that the plane won't "buck" if you use bind a key to use the "place wheel chocks" command before running the engine up.

Originally Posted by taly001

Maybe the fuselage damage model was made tough too prevent this snapping apart on ground.

IL2 doesn't simulate that sort of fuselage damage. I've never seen a plane in IL2 "break its spine" due to a hard three-point landing, even after suffering heavy fuselage damage. Such behavior would be very realistic, however, especially for planes like the FW-200, the B-24 (if ditched in water), and many carrier-based planes.

Originally Posted by taly001

What confuses me more is that the Ki-27 is a super-stable gun platform? Almost laser gun like!

I've got no problem with the Ki-27 being a stable gun platform. Soviet tests of captured examples, described it as being light on the controls, and possessing exceptional stability. But, IL2 doesn't model random turbulence which can affect even the most stable aircraft in flight (you see it on gun cameras where the shooting plane sometimes bounces around as it flies). Also, the Ki-27 vibrated constantly in flight, especially at high speeds as the wings started to get stressed. That would also affect accuracy. (Ditto for the P-39 which was also noted for vibrating during flight.)

http://www.j-aircraft.com/research/G...esky_of_vi.htm

"One well-preserved trophy Type 97 tested at the NII VVS, yielded very favorable flight evaluations. The fighter combined good speed with magnificent maneuverability, it had outstanding stability, and its flying characteristics were extraordinarily straightforward."

"Together with its strong side there were also deficiencies: The decreased weight led to complications in operation and transportation (the wing became detached), and most important, led to a decrease in durability and survivability. The aircraft lacked armor plating, the fuel tanks were unprotected, and were not filled with neutral gas, due to an absence of motor shock absorbers, the airplane vibrated continually in flight. Inadequate durability limiting the duration of a dive to about 500 to 700 m, was another deficiency of the Ki 27. Captured Japanese pilots testified that during a dive the wings began to vibrate, particularly the outer panels (on occasion resulting in their failure), and the motor quickly super.-cooled and might even stop."

"The greatest virtue of the Japanese fighter appeared to be its stability and ease of flying, which gave the pilot confidence, simplified the conduct of battle and gave a definite advantage. Thanks to its stability, the Ki 27 was able under all regimes of flight, with two machineguns, with the usual rate of fire of 1800 rounds a minute, bring sufficiently accurate and effective fire in battle . . . Another great virtue of the Ki-27 was the provision of a radio; there was a receiver on all aircraft, and on the machines of the flight commanders and higher a transmitter."

[Pursuivant]

Some evidence that perhaps the Ki-27 wasn't as fragile as the game makes it out to be:

http://img.imagesia.com/fichiers/d6/...d6am_large.jpg

[taly001]

Those Soviet VVS tests suggest that the il2 Ki-27 is pretty accurate in its flight and gunnery model. Although it probably should have vibrations starting from lower speeds, not just ~380kph+ like in game. Perhaps its such a good gun platform because the mg's are underneath the engine making the recoil forces balance out better.

It is the most fun plane to fly in il2, needing continuous pilot attention, incredible abilities but as many dangerous flaws! (against Buffalos and Hurricanes).

[major.kudo]

I think Ki-27 don't have to make weaker, too.
When behavior of AI and cockpit speedometer, and some others are improved, Ki-27 be more better plane in this game.

-

Originally Posted by Pursuivant

Some evidence that perhaps the Ki-27 wasn't as fragile as the game makes it out to be:

http://img.imagesia.com/fichiers/d6/...d6am_large.jpg

This picture's plane is not Ki-27. It's navy Type 96 Carrier based Fighter, "Mitsubishi A5M".
Pilot is IJN 1st class flight sergeant Kashimura.
In china front, he collided with P-36 during a battle.
But he learned extraordinary flight technique, and he landed at his base with this plane.

[Pursuivant]

Originally Posted by major.kudo

This picture's plane is not Ki-27. It's navy Type 96 Carrier based Fighter, "Mitsubishi A5M".

Thanks for the correction. Identification of the A5M and Ki-27 can be difficult from certain angles!

But, my point stands that early war Japanese planes perhaps aren't as fragile as IL2 "thinks" they are. Obviously, Sgt. Kashimura was the lucky exception the law of averages, but the picture proves that a plane like the Ki-27 (and, obviously, the A5M) can still fly with significant wing damage.

[majorfailure]

Originally Posted by Pursuivant

Thanks for the correction. Identification of the A5M and Ki-27 can be difficult from certain angles!

But, my point stands that early war Japanese planes perhaps aren't as fragile as IL2 "thinks" they are. Obviously, Sgt. Kashimura was the lucky exception the law of averages, but the picture proves that a plane like the Ki-27 (and, obviously, the A5M) can still fly with significant wing damage.

but I think it is rather a general IL2 problem than plane specific. IRL planes with missing wing sections were often still controllable e.g.:
http://www.sas1946.com/images/images...xfordcrash.jpg
or
http://i958.photobucket.com/albums/a...ps8e32bbf5.jpg

[Pursuivant]

Originally Posted by majorfailure

but I think it is rather a general IL2 problem than plane specific. IRL planes with missing wing sections were often still controllable

I agree. But, it's not necessarily the fault of the damage model.

Remember that in IL2 damage to the plane triggers a set of "damage textures, which overlay the base skin and make missing parts of the plane vanish. There are 3 levels: D0 (undamaged), D1 (light damage), D2 and (heavy damage).

When a part breaks, there's also an "end cap" model which appears.

Damage textures are made by artists, rather than flight modeler, so there is a great deal of "artistic license" in what sort of damage the D1, D2 represents. This artistry often isn't realistic.

Modelling errors come in when the plane breaks. The folks making 3D models (again, not necessarily that knowledgeable about how airplanes work) have to set the places on the model where parts break. If you set these break points incorrectly, you can get some very strange effects.

Artists' errors for "end cap" models (the graphic which appears after a part breaks off) can also make damage appear unrealistic.

If you wanted greater realism, someone would have to dig into each plane's flight model and figure the minimum wing surface area required for a damaged plane to fly. You then revise wing damage textures so that the D2 and endcap damage models are historically accurate.